The present invention relates generally to the dispensing of chemicals to agricultural fields. More specifically, the present invention pertains to a high accuracy GPS (Global Positioning System) based method and system for recording weather conditions as agricultural chemicals are dispensed to an agricultural field.
Crop-dusting is the term generally used for the dispensing of chemicals (e.g., fertilizers, pesticides, and the like) to an agricultural field (e.g., field crops, orchards, etc.) from a dispensing vehicle. During crop-dusting, the dispensing vehicle (e.g., tractor) makes numerous sequential, adjacent passes, dispensing chemicals in a swath across the field in each pass. The tractor""s driver carefully follows a ground track which ensures that each successive swath over the field is correctly spaced, distance wise, from the previous swath in order to avoid gaps or overlaps in coverage. For example, should one swath occur too far from a previous swath, the area of the field will not receive an sufficient amount of chemicals (e.g., pesticides, fertilizer, herbicides, and the like). Similarly, should one swath occur too close to a previous swath, the overlap area receives excessive amounts of chemicals. This can prove very expensive to the farmer. The crops of the field can be damaged or rendered unusable.
Certain types of agricultural chemicals needed to be closely tracked in order to ensure they are not inadvertently applied to neighboring fields. For example, while a particular agricultural chemical is selected specifically for application to the xe2x80x9ctargetedxe2x80x9d field, the inadvertent application of this chemical to a neighboring field can be highly undesirable. For example, the application of an herbicide to a crop that is specifically prepared for the herbicide is beneficial for the owner of the crop, while an inadvertent application of the herbicide to a neighboring crop that is not prepared for the herbicide is harmful to the neighboring crop. Hence, it becomes essential that the application of the agricultural chemical (e.g., the herbicide) is precisely controlled and precisely tracked.
Additionally, unusual types of field geometry (e.g., rectangular, circular, irregular, etc.) can make precise control of the chemical application operations more difficult. While conventional, rectangular, agriculture fields, having neatly ordered rows of crops laid out in a rectangular pattern, readily lend themselves to the orderly, rank and file, back and forth maneuvers of a crop-dusting tractor, circular/irregular types of fields are more difficult to ensure regular, even coverage.
Regardless of the field geometry, the presence of wind makes the chemical application operation much more difficult to control and track. The geometry of the agricultural field is constant, while the wind conditions during the application can be highly variable. Accordingly, the position of the dispensing vehicle needs to be closely tracked along with the wind conditions as the vehicle traverses the field.
Prior art FIG. 1 shows a diagram of a vehicle 101 dispensing chemicals across a first field (field A), which is adjacent to a second field (field B). As depicted in FIG. 1, the vehicle 101 traverses field A in an orderly, rank and file manner, as shown by ground track 102, dispensing chemicals as the vehicle proceeds. However the vehicle operator needs to exercise care as vehicle 101 approaches the southern boundary of field A. FIG. 1 shows a wind 103 blowing from the Northeast. Thus, as vehicle 101 traverses the southern boundary of field A, wind 103 greatly increases the likelihood that some portion of the chemical spray from vehicle 101 will be blown onto field B which lies immediately to the South. Accordingly, as shown in FIG. 1, that only must the ground track of vehicle 101 be closely monitored, the instantaneous wind velocity must also be monitored to ensure agricultural chemicals are not inadvertently dispensed onto the neighboring field B. This problem is made more difficult by the fact that the wind observed by the operator of the vehicle 101 is typically different from the true when due to the vehicle""s forward velocity.
Prior art FIG. 2 shows a diagram depicting the difference between the apparent wind 201 observed by the operator of vehicle 101 and the true wind 103. As described above, the problem of monitoring the true wind 103 to ascertain the location of the dispersion of the chemicals from vehicle 101 is made more difficult by the fact that the driver of vehicle 101 observes an apparent wind 201 due to the vehicle""s forward velocity. This is graphically depicted in FIG. 2, which shows the apparent wind vector 201 being comprised of a true wind vector 103 and a wind due to the vehicle velocity 203.
Hence, the driver of tractor 101 is incapable of accurately assessing the true wind 103 based upon observations made from tractor 101 as it traverses the field. This makes the dispensing of agricultural chemicals along boundaries between fields extremely hazardous. Although measurements of wind direction can be made prior to the actual dispensing operation, as is known, wind velocity can be highly variable. Wind conditions at the commencement of dispensing operations can be very different from wind conditions halfway through or near the end of dispensing operations.
Additionally, even in a case where the driver of tractor 101 accurately assesses wind conditions during dispensed operations, and dispenses agricultural chemicals in such a manner that no chemicals are inadvertently dispensed onto the adjacent field, the driver may still be liable at some later date for damage to the adjacent field. This is due to the fact that there exists no reliable means of accurately tracking wind conditions with respect to the vehicle""s location as the chemicals were being dispensed. Hence, the driver of tractor 101 is often unable to positively prove the prior dispensing operations are not responsible to any present damage to the adjacent field. In other words, the driver of tractor 101 is unable to positively prove he did not harm his neighbors field.
Thus what is required is a solution which accurately tracks wind conditions with respect to vehicle position. What is further required is a solution which accurately records field position during dispensed operations and the corresponding weather conditions which affect the dispersion of the chemicals dispensed. The record should be easily accessible with respect to time and position. In addition, what is further required is a solution which provides visual feedback wit h respect to the dispersal of chemicals and with respect to the weather conditions (wind direction, humidity, temperature, etc.). The method and system of present invention provide a novel solution to the above requirements.
The present invention provides a solution which accurately tracks wind conditions with respect to vehicle position. The method and system of the present invention accurately records vehicle field position during dispensed operations and the corresponding weather conditions which affect the dispersion of the chemicals dispensed from the vehicle. The method and system of the present attention provides a record that is easily accessible with respect to time and vehicle position. In addition, the present invention provides visual feedback with respect to the dispersal of chemicals and with respect to the weather conditions.
In one embodiment, the system of the present invention is implemented as a GPS weather data recording system for use with the dispensing of chemicals to agriculture fields. In this embodiment, a GPS receiver is used to determine a series of positions of a vehicle and vehicle velocity as the vehicle traverses an agricultural field. The series of positions trace the vehicle""s ground track across the agricultural field. A weather sensor (e.g., a wind sensor) is used to measure wind velocity with respect to the vehicle. A data storage system is used for storing data measurements, such as the series of positions and velocities from the GPS receiver and a series of corresponding wind measurements from the wind sensor. A computer system is coupled to the data storage system. The computer system receives the series of positions and velocities from the GPS receiver and the wind measurements from the wind sensor and is configured to compute a corresponding series of true wind velocities. This data is then stored with the series of positions into the data storage system such that a record of the true wind velocity with respect to the vehicle position is created.
The record can be referenced with respect to time to show the vehicle""s position on the field at a given time and the true wind velocity computations corresponding to that position and time. In this manner, the GPS weather data recording system of the present invention creates an accurate record of the vehicle field position during dispensed operations and the corresponding weather conditions which affected the dispersion of the chemicals dispensed from the vehicle. This allows the vehicle operator to positively to determine exactly where chemicals were dispensed and the weather conditions at the instant of dispensing which affected the dispersal of the chemicals, and thus determine and prove exactly where the agricultural chemicals landed.